1. Field of the Invention
The present invention relates generally to a damper control arrangement for manually operating a louver of a damper for adjusting flow direction and/or flow amount of air. More specifically, the invention relates to a damper control arrangement which is suitable to be employed in an automotive air conditioner system for controlling discharge of conditioning air into a vehicular cabin.
2. Field of the Invention
As is well known, automotive air conditioner systems employ a sort of damper for selectively discharging conditioning air into the vehicular cabin. Each damper is associated with a louver which is mechanically coupled with damper control mechanism so as to mechanically control the louver position depending upon the discharge mode of the air conditioner system. In addition, some of the dampers, such as those used in chest vent or vent outlet, are provided capability of direct access to louvers via a louver associated operation lever or operation dial in order to permit the passengers in the vehicular cabin to adjust the discharge direction and/or flow amount of the conditioning air.
Such manually operable damper control arrangements for the automotive air conditioner system have been disclosed in Japanese Utility Model First (unexamined) Publications (Jikkai) Nos. 55-166347 and 60-135218. The damper control arrangements disclosed in these published Japanese Utility Model Applications, comprise damper housings defining conditioning air paths and louver assemblies disposed within the damper housing and operable for varying the angular position for controlling flow direction and/or flow amount of conditioning air. The louver assembly is associated with a manually operable operation lever or operation dial via a boss extending therefrom. The operation lever or dial is connected to the boss directly by means of a screw or via an elastic body, such as bushing. In such conventional arrangements, the operational torque for manually controlling angular position of louver or louvers of the louver assembly can fluctuate depending upon tightening torque of the screw. Therefore, operational torque cannot be stable to degrade operation feeling.
The aforementioned Jikkai 60-135218 has therefore proposed avoidance of degradation operation feeling by providing a click mechanism. In the proposed construction, notching or recesses are formed in one of a bushing and manual operator, e.g. operation lever or operation dial, and click member, such as a ball is provided to the other of the bushing and manual operator. The proposed click mechanism is successful to provide click feeling for one predetermined direction of louver operation. However, since the manual operator is supported by means of the bushing at the pivoting center and establish click engagement at a position offset from the pivoting center, fluctuation of operational torque is caused when composite operational force in more than one operational direction is exerted on the manual operator. Therefore, such prior proposed arrangement is not satisfactory to provide stable operation of the damper and thus provide good operation feeling.